I think what you should offer is Tor forwarding(especially with such limited resources), that is have it set up so that your server has multiple Tor (or i2p) addresses, and then forwards the traffic from those addresses over a https connection/tunnel to another server(which only you and your client know, don't keep any traffic records).
This will allow others to get onto Tor and run services from there without the hastle of having to run their own node software(which is a real pain), it also means that you will probably be able to get the most out of what little resources you have.
You can certainly do this with i2p, I'm not sure about Tor, is it possible to have multiple .onion addresses for a single Tor node?
At least, this is definetly a service that I want (and I'm willing to pay for), I think others would really want this too and you could easily charge a modest fee. Help people register a .i2p address that goes to the server too, would be great.
This is an area that my syndicate will be moving into in the future (after a few other things are taken care of), safe, secure hosting withing cypherspace.
the problem with only providing tor forwarding, it that its at least as difficult as setting up tor yourself...
what i am offering is that you get a simple solution where you get a normal ip address(eg. 10.1.0.50) on a private subnet(eg. 10.1.0.0/16).
you run your service as normal, and then having a little nice web interface where you map random_tor_address.onion:port to 10.1.0.50:port. simple, clean and easy.
of course when i get users/money enough i will buy a new bigger and better server andmuch more bandwidth.